Thermometer.



J. E. ROBINSON.

THERMOMETER.

APPLICATION FILED NOV, 14, 1914.

1 182,423, Patented May 9,1916.

d I v 7% wzrzwgg 67 W 3 JAMES E. ROBINSON, or cmcaeo, ILLINOIS.

THEBMOMIETER Specification of Letters Patent.

Application filed November 14, 1914. Serial No. 872,074.

To all whom it may concern Be it known that I, JAMES RoB NsoN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Thermometers, of which the following is a specification.

My invention relates to thermometers.

One of the general objects of my invention is to improve thermometers.

A specific object of my invention is to support or set the thermometer indicating tube in such manner as to render it, to a large extent, immune from breakage, due to sudden and violent shocks or continued tremor or vibration.

Another object of my invention is to provide conducting means, as a part of the in strument, whereby to transmit the temperature of a medium to be tested, to the mercury tube, from regions too remote to be practically reached directly by the relatively fragile tube.

Still another object of my invention is to shield the lower end of the indicating tube whereby to protect it, to some extent, from the effect of the medium that may immediately surround that portion of the instrument, as for instance, steam in the space above a body of water, thereby rendering the reading indicative of the water temperature rather than that of the resulting steam or. vapor.

Another object of my invention is to render the lower portion of the heat conductor an absorbent of heat and the upper portion therefore a reflector of heat, thereby to more accurately indicate the temperature of the medium in contact with the lower portionof the instrument.

Other and further objects of my invention will become readily apparent to persons skilled in the art from a consideration of the following description when taken in conjunction with the drawings, wherein Figure 1 is a vertical, sectional view of an automobile radiator showing my thermom eter secured to the filling cap closing the said radiator. Fig. 2 is an enlarged elevation of the thermometer. Fig. 3 is an elevation, part in section. Fig. 4 is a section, taken on line 41 of Fig. 3. Fig. 5 is a section, taken on line 55 of Fig. 3. Fig. 6 is a section, taken on line 66 of Fig. 3. Fig. 7 is a sectional view of the parts composing the head of the thermometer, showing them superposed tions.

In all the views the same reference characters are employed to indicate similar parts.

10 is a head of the thermometer or instrument, comprising a metal tube 11 interiorly screw threaded, as at 12, and provided with in their relative posia cover cap 13. A glass tube 14 somewhat,

shorter than the tube 11, fits neatly within the latter tube and covers and protects the indicating tube 15 from changes of temperature by the inclusion of the annular imclosed dead air space that exists between the tube 14 and the tube 15. The tube 11 is cut away, at opposite sides as at 16 and 17, for observation of the indicating tube 15 through the substantially transparent glass tube 14. A disk 18 is adapted to screw into the lower end of the tube 11 and is provided with an interiorly and exteriorly screw threaded tubular extension 19. I

The indicating tube 15 is yieldingly mounted and securely held in the head 10 in the following manner: A metal washer 20, having an orifice 21 considerably larger than the diameter of the tube 15, is placed in the cap 13, and under the washer 20 is a soft rubber washer '22, which has more or less intimate contact withthe upper end of the tube 15. A similar rubberwasher 23 is placed over the lower end of the-glass 'tube 14, in a manner similar to the position of the upper washer 22, and a metal washer 24, similar in every respect to the washer 20, is placed next to the yielding rubber washer 23. Before the indicating tube is pushed through the orifices provided in the washers referred to, rubber cement 26 is placed in said orifices, after which the indicating tube 15 is pushed into position, entering the upperend thereof in the tubular portion 19, and pushing it through the apertures provided in washers '23 and 24 and subsequently through the washers 22 and 20 until it has reached the Patented May '9, 1916.

position determined for the proper calibration of the instrument. It is then left undisturbed until the rubber cement 26 dries which on account of its adhesive qualities for the glass stem 15 will securely hold it in its proper place. It will, therefore, be observed that the indicating tube 15 is yielding and vertically held by the rubber suspension in its proper position and that of radiating or any shock orvibration transmitted to the head 10 is absorbed by the rubber support and does'not reach said stem 15. To protect the lower end of the tube 15 and the mercury bulb 15 thereof, and to conduct the temperature of the water to be tested, I provide an extension heat conductor 31, screw threaded at its top end, as at 32, and adapted to screw into the tubular extension 19 of the head 18. It is bored out at its upper end, as at 33, to admit the mercury bulb 15 and the boreis partly filled with free mercury 34, or other suitable conducting material, such as oil or the like, to make more intimate contact between the conducting element 31 .and said bulb.

As the lower end 31 of the conducting element 31 is to be submerged in the water, as shown in Fig. 1, and inasmuch as it is the temperature of the water that is desired to be ascertained I prefer to coat this end of the conductor with a black paint or japan, or other heat absorbing medium 31*, as shown more clearly in Fig. 6, and I prefer to polish the upper portion 31 by nickel plating, or the like, so that this portion, which is normally within the steam space 34, of the radiator 35, will have the efi'ect dispersing the heat that would otherwise be absorbed from the steam.

The tubular threaded stem 19 of the instrument, is adapted to be screwed into the closure cap 35, of an automobile radiator 35 and the conductor 31 is adapted to pass down through the steam space and into the water 30 included in said radiator, so that the true temperature of the water may be ascertained by the rise of the mercury within the tube 15, which reading may be made by the driver,- through the protecting tube 14. Three indications are shown on the outside of the tube 11, to wit 130, 170 and 212 indicating the temperature of the water within the radiator, when the mercury has arrived at either of these various points of indication, so that the driver will thereby be advised as to the relative temperature of the circulating, engine-cooling water.

After the parts have been assembled, in

a manner heretofore described, they are tightly screwed together and secured in position, so that the mercury tube 15 is protected against accidental breakage, by the conductor 31, and is so supported within the head 10 as to be subsgintially unaffected by jar or vibration due to the motion of the automobile to which it may be applied.

It is evident that my device may be employed for other purposes than that described and various changes in the form and configuration and disposition of the parts ma be effected without departing from the spirit and scope of the appended claims.

Having described my invention, what I claim is 1. A thermometer comprising a tubular head cut away on opposite sides to provide observation orifices; a concentric glass tube within said head; rubber washers closing the ends of said glass tube to provide a dead air space therein and an indicating tube of a thermometer extending into said glass tube and sealed in the axial orifices of said washers to hermetically close them and to flexibly suspend the tube.

2. A thermometer comprising a tubular head cut away. on opposite sides to provide vertically elongated observation apertures; a cap closing the upper end of said head; a glass tube within said head; a rubber washer between the upper end of said tube and cap; means for closing the lower end of said head; a rubber washer between said means and the lower end of said glass tube and an indicating tube of a thermometer extending into said head, through said washers and cemented to said washers, to hermetically closesaid glass tube and to flexibly suspend the indicating tube.

3. A temperature indicator adapted to be inserted through an opening in, and supported by, the cap of an automobile radiator, comprising a comparatively short thermometer, means whereby the same is perma nently secured in said cap with its reading stem extending above it and its bulb projecting a short distance below the cap, a comparatively long thermo conductor adapted to extend well below the normal level of water in the radiator and having an opening formed in its upper end and means for sealing the thermometer bulb within the said opening. 4. A temperature indicator adapted to be inserted through an opening in, and supported by, the'cap of an automobile radiator, comprising a comparatively short thermometer, a support therefor mounted on the radiator cap and to which the thermometer is permanently secured with its reading scale projecting above the cap and its bulb extending a short distance below the cap, a comparatively long thermo conductor connected with said support and adapted to extend well below the normal level of water within the radiator, said thermo conductor having an opening in its upper end to receive the thermometer bulb, and means having high thermo conductivity tvithin the opening for intimately connecting said thermo conductor with the bulb.

5. A temperature indicator adapted to be inserted through an opening in, and supported by, the cap of an automobile radiator, comprising a supporting and incasing member, a comparatively short thermometer permanently secured to said member with its reading stem extending above the radiator cap and its bulb projecting a short distance therebelow, and a comparatively long thermo-conductor connected at its upper end with said member to transmit heat from its lower portion to the thermometer bulb and adapted to extend well below the normal level of water in the radiator.

6. A temperature indicator adapted to be inserted through an opening in, and supported by, the cap of an automobile radiator, comprising a supporting and incasing member, a comparatively short thermometer permanentlysecured to said member and p0- sitioned with its reading stem extending above the radiator ca and its bulb projecting a short distance t erebelow, a comparatively long thermo-conductor connected at its upper end with said member to transmit heat from its lower end to the thermometer bulb and adapted to extend well below the normal level of water in the radiator, the upper portion thereof being highly polished and a coating of heat absorbing material on the lower portion.

7. A temperature indicator for the cooling system of an internal combustion engine and adapted to be inserted through an opening in, and supported by, the filler cap of the radiator, comprising a supporting and incasing member, a comparatively short thermometer permanently sealed in said member with its reading stem extending above the radiator cap and its bulb projecting a short distance therebelow, aj comparatively long rod of metal having high thermoconductivity adapted to extend well below the normal level of water in the radiator and having a shallow recess formed in its upper end to receive the bulb of the thermometer, and means for connecting the upper end of said rod with the supporting and incasing member.

In testimony whereof I hereunto set my hand in the presence of two subscribing witnesses.

Fomim BAIN, MARY F. ALLEN. 

